Finally getting around to posting the info on how I mounted
snowpro's with 4D discs onto my Burton board. Mostly for posterity
in case anyone else wants to do this at some point.

The SnowPro Race bindings don't have the center hole and round
disk that sits into it like many other bindings. Instead, they
machined out 4 kidney bean shaped holes that sit over the holes
in the board. Then, the disc sits directly on top of the plate
and its holes will line up with the holes in the board through
the holes in the plate.

As a result, drilling a new hole to make a triangle for my
Burton Canyon would require me to drill through the disc and through
the binding. Then of course, I'd only have 3 screws holding it
down, and secondarily, I'd have to guess at my binding angles
on the first drilling and never adjust them or drill lots of holes,
which I wasn't too thrilled about.

I noticed however, that 4 of the holes on the burton board
came pretty close to a square. (see Burton four holes.bmp I've
shown in red the square. Should be the case on all Burtons I think...)
In my experiments, I could *almost* get the 4 holes to line up
inside the holes on the bindings.

So, with a small grinding tool, I widened the holes on the
bindings by about a 3mm each and widened the holes on the discs
and managed to get all 4 to line up properly. In the "Drilled
out Close up" pic, you can see that they were about 1/2 wide
- the left binding isn't drilled out and I widened them just a
smidge more than 1/8 inch - the right binding. The mods to the
discs were also minor. "See the Drilled Out Discs,"
all I really did was widen the end of the slots. As it stands
now, they function almost as they should; I can loosen the discs
and adjust my angles infintely and I have 4 screws down tightly.
The only thing I think I've lost is the ability to slide the disks
in their slots for minor back and forth adjustments.

I was careful to evenly drill out the holes on the bindings
so as to not upset their structural integrity. By taking a little
from each of the holes, none of them was drilled out so much as
to weaken them. I guess they are weakened somewhat by the missing
3mm but it seems nominal.

Now, there's only ONE place on the board where these 4 holes
line up. On my Canyon 168, it turned out that the center of the
front disc is 60cm from the nose and the center of the back disc
is 54 cm from the tail. That left about a 54cm stance for me.
I'm sure when my new carve board shows up and I can play with
those figures I'll develop something else to suit me, but I can
make this board carve with those settings.

I've included one pic of the board with the boots mounted at,
I think, 55/55. Amazing that even with a 27cm waist board, 29.5
boots still get near the edges...

Hope this helps anyone else looking at something like this.
Also would like comments from anyone on this - in case there's
something about these mods that I've overlooked and will lead
to problems.

It looks great. The only concern I would have is how much
you miss the "sweet spot" on a Burton freestyle board.
You know, the factory recommended mounting position when you
use their 3-hole bindings. In order to compute this correctly
you need to note the markings on the board, of course, but in
addition you must use a Burton 3-hole disk as a template because
the 3-holes are not centered within the disk. There is some degree
of offset.

But if you hit close to that mark you will have a fore/aft
binding position that works acceptably well. My Burton boards
all have bindings on them at this moment, so I can't take an
easy look, but if you are close to the mark I would be very interested
as I would like to use a 4-hole binding on my 3-hole Alp.

God knows the things I have done to my Burton Mousetrap bindings
(stepin race plates) and to my Ride/Preston EX bindings with
a drill and a hacksaw! I know the urge to modify. It never ceases
to amaze me some riders will not even change the binding angle
(that some 15 year old kid pulled out of his ass) when the board/binding
combo was sold. Or suggest modifying the angle of the highbacks
to them? Heaven forbid!!!! That was all done by "the experts"
at "the shop".

Date: January 08, 2003 06:43 PM Author: aaron (volvo1@gte.net) Subject: what I did

I ran into the same situation, this is what i did. The snow
pro discs are pretty much just a round disc with a centering pin
and 4X4 mounting pattern. I took the original Snowpro discs to
my local machine shop along with a burton 3D disc. They machined
two discs out of aluminum with the 3D pattern. I then took out
my dremel tool and extended the kidney bean holes that are on
the actual binding plate, being careful not to take off too much
material. The holes for the bindings, the discs and board fall
within millimeters of each other so you don't have to do much
grinding to get everything to align. I realize that I only have
three screws holding the plates on now, instead of the original
four but the aluminum plate that the toe and heel bales mount
to is fairly thick(5 mm approximately). Everything seems to function
great and I am standing in the sweet spot of the board. The discs
cost only twenty dollars to have made.